Boston’s Logan Airport, for
example, has been using 20 roof-mounted wind turbines on the airport’s
administration centre to generate electricity for the building since 2008. This
amounts to roughly 2% of the office complex's monthly power consumption. Copenhagen’s
Kastrup Airport began installing energy-efficient heat
exchangers in 2010 to manage terminal temperatures, and Denver International Airport has access to
an eight megawatt solar array system, one of the largest airport systems in the
US, which has been providing 6% of the
airport's electricity since July 2011.

“Climate change is an issue that is
affecting everyone, and airports have their own part to play in finding a
solution,” said Gary Hodgetts, director of operations at London City Airport.

However, going green is not just a matter
of corporate social responsibility; it is also something that will reduce airport
running costs. “This can lead to increases in air service as airlines find
lower costs attractive,” said David Magana, a senior manager at Dallas Fort
Worth Airport. “And passengers do notice when airports attract more air
service.”

To date, 64 European airports have signed
up to the Airport Carbon Accreditation
Scheme, a voluntary initiative launched in 2009 that aims to reduce emissions
from ground transport, boost the use of renewable energy and increase the
energy efficiency of airport terminals. The scheme – which accounts for more than half the region’s air passenger
traffic (780 million passengers each year) – includes some of Europe's busiest hubs,
including Frankfurt, London’s Heathrow and Paris’ Charles de Gaulle. The scheme extended
its remit last year to cover Asia and the Middle East, where six airports have signed
up, including Mumbai, Abu Dhabi and Singapore’s Changi airports.

And the scheme is working. Helsinki Airport, for example, has
cut its carbon dioxide emissions by nearly 2,500 tonnes compared to 2011, by
making heating, ventilation and lighting more energy-efficient, as well as
using electrically-operated vehicles. “This corresponds to an emissions
reduction of 0.4kg per passenger, or the amount of fuel transported by 23
container trucks,” said Heini Noronen-Juhola, vice president at Helsinki
Airport.

Going green at an airport is not always easy.
For instance, if renewable energy sources such as solar panels and wind
turbines are installed on-site, they have to be clear of runways and air traffic
control towers. But it is clear that airports can reap the rewards over time. Athens,
Greece has one of the largest airport solar power plants in the world,
supplying 8.05 megawatts of electricity to the terminals, with this source of
renewable energy accounting for 10% of the airport community’s needs, from
lighting to heating. This has resulted in an estimated
cost savings of one million euros over the last six years.

The leading challenge with solar power,
however, remains the storage of energy during the day for use at the airport at
night. A lot of progress is now being made with manufacturers testing new
battery technologies, but this is not yet in use commercially.

However, even if the airports themselves are
trying to reduce their emissions, it is difficult to control all the
concessions and sub-contractors that work within big airports. Copenhagen alone
has 500 companies operating on-site and roughly 23,000 employees.

“We estimate that around 94% of the emissions
per passenger stem from sources outside our direct control,” said Inger Seeberg
Sturm, head of environmental affairs, at the airport.